Embarrassing newbie questions on oil changes...

[G12atlast_LAPSED]

Hmm, I'm the proud owner of a G12 (late 1960) for which there appears no 'routine maintenance' handbook is available. So, despite numerous BSA/Triumph/Ariels and all the rest, I'll have to ask some silly questions as the 'workshop manual' that is available jumps right into rebuild mode, bypassing 'stupid owner' mode on the way!

Draining the oil from the tank - I'm assuming that I disconnect the feed pipe at the front timing side of the engine, and that there is no gauze filter in the tank? My pipes are both clamped firmly to the tank spigots as far as I can see. I'm assuming the forward entry pipe on the timing chest is the feed from the tank and the one to disconnect and that the rear pipe is the return to the tank/rockerboxes. Dowty washers, perhaps?

Primary chaincase is next... I'm not sure I can spot the drain plug - is it the large screw in front of the footrest, or is that the level plug? And, if that isn't the level plug, where is it? Primary chaincase oil - straight 50 like the engine, or 20/50?

Gearbox - drain plug fine here - but is there a level plug too?

Many thanks, you wouldn't believe how I've resisted asking these questions.

Cheers,

Simon

[dave16mct]

The 1960 handbook is available, sure I've got one? Anyway..To drain the oiltank....unscrew the oiltank drain screw! Don't touch the pipes, except remove the feedpipe from the oiltank and wash the gauze filter. Also drain the sump.
The primary chaincase drainscrew is near the bottom. The large one is to put oil in. Only just touching the very bottom of the chain. I put 20/50 in mine but some use 50 and others ATF. (gives you a lovely cluch but usually leaks too.) On the gearbos be very carefull not to undo the large domed plug, it contains the detent spring and plunger. the drain plug is there but harder to see. The level plug is on the back and can just be seen through the filler cap hole, (when reomverd!) Use straight 50.
Dave.

[Janet]

you wouldn't believe how I've resisted asking these questions.

Welcome to the club.

I can't help you with any advice about your bike but I am an expert at asking stupid questions. If you don't ask, how on earth are you going to learn? You would be doing a lot of other people a favour. Think back to your schooldays when you didn't understand something but were afraid to ask. Then, when you or a classmate did pluck up the courage to show your ignorance, others in the class would suddenly sit up and take notice. Therefore one question could provide an answer to several people. Keep up the good work.

[Rob Harknett]

You should have a choice literature that will answer the basic questions. Books for 1960 twins or heavyweight singles AJS or Matchless. Bit earlier or bit later. Here's a couple to get you going.
http://archives.jampot.dk/book/Owners_m ... Models.pdf
http://archives.jampot.dk/book/Workshop ... models.pdf

[G12atlast_LAPSED]

Excellent, thank you. That owners instruction book is exactly the thing. I'll be printing and binding it.

Here we are yesterday getting a blessing from on high at Wells Cathedral.



I've had a lot of classics but rarely ones that tick over so well and fail to leak much oil - this does both and, to my eyes, is such a pretty thing. I'm very lucky to have it.



So, just checking... No 1 here is the large inspection cap and I fill the chaincase to the bottom of this with engine oil, whilst No 2 is the drain screw. Hope that's correct.

Cheers

Simon

[dave16mct]

Correct, except don't overfill. Only fill just to the very bottom of the chain. Don't forget that chain whip will fling it everywhere inside the case.

[leswaller]

It is quite interesting that even though the original owner's manual tells you to check the oil level regularly, and the diagram shows the min and max levels for the oil, nowhere does it explain how to check the level. I have been trying to discover the best way to do this for several years without success
Apart from sticking a metal rod down inside the tank and then holding it against the outside to check the oil level (and dripping oil all down the side of the tank in process), does anyone have any suggestions for the best way to check the level on this particular type of tank which has a baffle across the filler hole

[Janet]

If it's possible to put a metal rod down the inside of the tank, can you not make a dipstick with upper and lower level marks on it, measured from the heights indicated in the manual? If it isn't possible to fasten it to the filler cap (something Louis de Grave made for for my lightweight, but they're different ) it should be possible to fix a cross-piece at the filler level, to give the correct measurement.

[Rob Harknett]

I am not familiar with the oil tank that has the baffle. If you cannot see the oil, is it not possible to keep a length of wire, to use as a dip stick. You could go back to the very early days when they had sight glass's . You could fit a bit of angled copper pipe top and bottom of the tank joined with clear tube. But this is something else that could leak or break, and loose all your oil, petrol, water what ever. Probably why they soon got discontinued.

[leswaller]

Rob, afraid that's not possible as I have installed an external full flow oil filter so the oil pipes don't go anywhere near the side of the tank.

Janet, that is food for thought. Due to the internal baffle that goes across the top of the tank about 1" down from the filler neck it is not possible to fit anything to the filler cap, but the baffle, which has gaps round the edge, might help to locate the dipstick if i made it in the shape of an inverted L with the horizontal leg curled to fit round the metal oil return pipe so that it doesn't make a break for freedom inside the tank. Have a look at page 13 of the booklet in this link from Rob
http://archives.jampot.dk/book/Owners_m ... Models.pdf, however what the diagram doesn't show is the fixed and welded baffle plate on the right hand section of the tank which sits about 1 " above the max oil level.
Now that you have given me the idea I think some experimenting by bending some welding rod is called for, thanks.